Typically, clapboard siding panels, such as fiber cement clapboard siding panels, are installed on a wall of a structure, generally on a sheathing product, in one of two ways—either in a so called “blind nail” method or a so called “face nail” method. In the blind nail method, illustrated by siding panel assembly 20 of FIG. 2, a first siding panel 16a is aligned on the face of a wall 12 and a nail (not shown) is driven through the panel 16a, generally through an upper region of the exterior face of the panel 16a, into the wall 12. A second panel 16b is then secured to the wall 12 in the same manner using nail 18. The second panel 16b overlaps a portion of the exterior face of the first panel 16a and covers the nail or fastener driven through the first panel 16a. Another panel (not shown) is then installed overlapping panel 16b and covering nail 18. The blind nail method, although aesthetically pleasing, generally provides less wind load resistance (i.e., resistance to detachment from the wall under wind load), when compared with the face nail approach described below. With more brittle siding panels, smaller face exposure or face nailing is generally required for high load areas.
In the face nailing method shown by panel assembly 10 of FIG. 1, the first siding panel 14a is properly aligned on the wall 12. A second siding panel 14b is then aligned overlapping the first siding panel 14a, as described above, and a nail 18a is driven through both siding panels 14a, 14b, exposing the head of the nail 18a at the exterior surface of the second siding panel 14b. This process is repeated with subsequent siding courses, such as panels 14c and 14d shown in FIG. 1, using nails 18b and 18c. This method provides greater wind load resistance because each panel is secured by twice as many nails when compared with the blind nail method described above, i.e., each nail is driven through two panels (e.g., panels 14a, 14b) as opposed to just one panel.
There is a growing concern in the siding industry regarding “rainscreen.” Rainwater penetration in a wall surface is a concern with any siding product, particularly in high storm areas. This penetration can cause rotting and decay and has been identified as the cause of massive condominium failures in regions such as Nova Scotia. Generally, there must be three factors present for leakage to occur: (1) water must be present; (2) an opening in the wall must be present; and (3) there must be some kind of force present to move the water through the opening. The above-described face nail and blind nail installations tend to pull the top panel onto the overlapped panel to create a fairly tight overlap. This overlap can cause a pressure imbalance between the outer and inner surfaces of the overlapping panels, thereby providing the force necessary to draw water into the assembly towards the wall. A related issue is draining water away from the wall once it penetrates the assembly.
These concerns have engendered the use of vertical furring strips in installing clapboard siding panel assemblies. The siding panels are installed onto the furring strips over some form of water barrier, such as building paper. The furring strips act to slightly separate the rear face of the siding panels from the wall, creating a slight air gap that helps to equalize air pressure on the front, exterior and rear, interior faces of the siding panels. This helps reduce the amount of moisture that is pulled to the rear face of the siding panel, which can lead to moisture-related problems such as mold growth or wall rotting stemming from collected water or moisture. This gap, which is created by the furring strips, also provides for a rain drip or weep, which helps remove water from behind the rear face of the siding panels. The use of furring strips, however, is not without its disadvantages, including increased installation costs due to the extra materials and the cumbersome installation process.
In light of the above, there is a need for a new siding panel system and panel configuration that allow for ease of installation while providing rainscreen and water drainage.